There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

A bridge is about to collapse. There are four people P, Q, R and S on one of the sides. Before the bridge collapses, they want to cross it. Now since the bridge is too weak, it can only stand the weight of two people at a time. Also, it is night time and nothing is visible. They have just one torch with them.

Now P takes one minute to cross the bridge, Q takes two minutes to cross, R takes five minutes to cross and S takes ten minutes to cross.

The bridge will collapse in seventeen minutes. How will they be able to cross the bridge before it collapses?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

What is black when you buy it, red when you use it, and gray when you throw it away?

What do you call a fish without an eye?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

Give it food and it will live; give it water and it will die.